Abstract: Study on oxidizing cotton fiber to oxycellulose by sodium periodate solution was carried out,and FT-IR,XPS were used to analyze the micromechanism of oxidized cotton fiber and the oxidized cotton fiber treated by fibroin solution.It was indicated that dialdehyde cellulose was gained after oxidizing,the aldehyde was increased,hydroxy and hydrogen bond was decreased and the cellulose molecule was degraded during oxidizing;imine covalence formed between aldehyde group and amido when oxidized cotton fiber was treated by fibroin solution.